An effective way to correct people’s falsely held beliefs is to address them directly with evidence. However, such rebuttals can sometimes backfire, leading people to double-down on their original position. A new paper published in Discourse Processes suggests why: when people read information that undermines their identity, this triggers feelings of anger and dismay that make it difficult for them to take the new facts on board.

Past research had suggested that one reason changing minds is so challenging is that exposing someone to a new perspective on an issue inevitably arouses in their minds the network of information justifying their current perspective. An arms race ensues: when the new complex of information overwhelms the old, often by integrating some of the existing information (yes, yoghurt contains bacteria, but bacteria can be helpful), persuasion is possible. If not, the attempt fails, or even backfires, as the old perspective is now burning even more fiercely in the person’s consciousness.

However, the new research led by Gregory Trevors was motivated by the idea that the backfire effect may not be about which side is winning that mental arms race at all. Instead, these researchers believe the problem occurs when new information threatens the recipient’s sense of identity. This triggers negative emotions, which are known to impair the understanding and digestion of written information.

Trevors’ team tested their theory with a study on genetically modified foods – a subject rife with misconceptions, such as that hormones are involved in making them. The researchers assessed 120 student participants for their prior knowledge and attitudes to genetically modified organisms (GMOS) and their need for dietary purity, measured by items like “I often think about the lasting effects of the foods I eat.” This was the key variable of interest because it was intended to tap into how important food purity was to the participants’ sense of identity. The researchers specifically wanted to find out whether this identity factor would influence how people felt when their beliefs were challenged, and whether they would comply with, or resist, the challenge.

After the researchers gave participants scientific information worded to directly challenge anti-GMO beliefs, those with higher scores in dietary purity rated themselves as experiencing more negative emotions while reading the text, and in a later follow-up task, they more often criticised GMOs. Crucailly, at the end of the study these participants were actually more likely to be anti-GMO than a control group who were given scientific information that didn’t challenge beliefs: in other words, the attempt to change minds with factual information had backfired.

In further analysis, the researchers directly tested the claim that the identity factor had disrupted the learning of new pro-GMO information, but there was no evidence for this. Although negative emotions were weakly associated with lower post-test learning on a short quiz, participants at all levels of dietary purity performed at a similar (poor) level.

So we can reasonably conclude from this study that threats to a person’s identity do cause resistance to taking new factual arguments on board, and we know negative emotions seem to play a part, but we need more research to fully understand why this leads to a backfire effect.

If persuasion is most at risk of backfire when identity is threatened, we may wish to frame arguments so they don’t strongly activate that identity concept, but rather others. And if, as this research suggests, the identity threat causes problems through agitating emotion, we may want to put off this disruption until later: Rather than telling someone (to paraphrase the example in the study) “you are wrong to think that GMOs are only made in labs because…”, arguments could firstly describe cross-pollination and other natural processes, giving time for this raw information to be assimilated, before drawing attention to how this is incompatible with the person’s raw belief – a stealth bomber rather than a whizz-bang, so to speak.
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